William Shawn was born in Chicago, Illinois, the son of Benjamin T., a well-to-do cutlery merchant of Central European origin, and Anna Bransky Chon. He was the youngest of five siblings including Harold Irwin (1892–1967), Melba (born 1894), Nelson Allen (born 1898), and Myron Edward Chon (1902–1987). His family were non-observant Jews.[1] Chon dropped out of the University of Michigan after two years (1925–1927) and began working.

He traveled to Las Vegas, New Mexico, where he worked at the local newspaper, the Optic. He returned to Chicago and worked as a journalist. Around 1930 he changed the spelling of his last name to Shawn. In 1932, he and his wife, Cecille, moved to New York City, where he tried to start a career as a composer.[citation needed]

Shawn rose to assistant editor of The New Yorker and oversaw the magazine's coverage of World War II. In 1946, he persuaded the magazine's founder and editor, Harold Ross, to run John Hersey's story about the atomic bombing of Hiroshima as the entire contents of one issue. He left for a few months shortly after that to write on his own, but soon returned.[citation needed]

A few weeks after Ross died in December 1951, Shawn was named editor. Shawn's quiet style was a marked contrast to Ross's noisy manner. Whereas Ross constantly wrote letters to his contributors, Shawn hated to share anything, especially on paper. His shyness was office (and New York) legend, as were his claustrophobia and fear of elevators; many of his colleagues maintain that he carried a hatchet in his briefcase, in case he became trapped.

Shawn would buy articles and then not run them for years, if ever. Members of the staff were given offices and salaries even if they produced little for the magazine; Joseph Mitchell, whose work had appeared regularly during the 1950s and early 1960s, continued to come to his office from 1965 until his death in 1996 without ever publishing another word. But Shawn did give writers vast amounts of space to cover their subjects, and nearly all of them (including Dwight Macdonald, Hannah Arendt, and England's Kenneth Tynan) spoke reverently of him. J. D. Salinger in particular, adored him, and dedicated Franny and Zooey to Shawn.[2]

When Advance Publications bought the magazine in 1985, the new owners promised that the magazine's editorship would not change hands until Shawn chose to retire. But speculation about Shawn's successor, a longtime topic of publishing-world chatter, grew. Shawn had been editor for a very long time, and the usual criticism of the magazine—that it had become stale and dull—was growing more pointed. Advance chairman S. I. Newhouse forced Shawn out in February 1987, and—after reportedly telling Shawn that he would honor his request to name his deputy Charles McGrath to succeed him—replaced Shawn with Robert Gottlieb, the editor-in-chief at the well-regarded book publisher Alfred A. Knopf.

Shawn married Cecille Lyon (1906–2005) in 1928, and the couple had three children, writer and character actor Wallace Shawn and composer Allen Shawn. Allen's twin sister, Mary, is autistic and resides at an institution in Delaware. In 2007, Allen Shawn published a memoir, Wish I Could Be There, centering on his own phobias.[citation needed]

In 1996, William Shawn's longtime New Yorker colleague Lillian Ross revealed in a memoir that she and Shawn had engaged in an extramarital affair from 1950 until his death, with Mrs. Shawn's knowledge. Ross reported that Shawn was active in the upbringing of Ross's adopted son, Erik.

In 1998, Indian author Ved Mehta, who had worked with Shawn at The New Yorker for almost three decades, published a biography of Shawn entitled Remembering Mr. Shawn's New Yorker: The Invisible Art of Editing.